An efficient pressure-aware character input algorithm for mobile phones

Opportunities and needs are increasing to input Japanese sentences on mobile phones since performance of mobile phones is improving. Applications like E-mail, Web search and so on are widely used on mobile phones now. We need to input Japanese characters using only 12 keys on mobile phones. The letter cycling input method is most commonly used for the input of characters on mobile phones. In this method, a chosen key represents a consonant and the number of pressing it represents a vowel in Japanese. It is troublesome for a user because the input method needs several key-presses per Kαηα-character. We propose a pressure-aware input method for mobile phones. In our proposed method, a user is able to input a Kαηα-character per key-press. The pressed key represents several Kαηα-characters and has ambiguity. Our proposed method uses pressure of the pressed key for the disambiguation. Strength of a key-pressure means a vowel in our proposed method. A user presses a key by the pressure-strength corresponding to the intended vowel. Therefore, a user is able to input a Kαηα-character per key-press and input Japanese characters rapidly. Our proposed method corrects the errors in Kana-Kanji translation since the Kana-characters inputted by pressure may have errors. Thus, our proposed method enables us to realize rapid input of Japanese text on mobile phones. We show processes of our proposed method and also show the effectiveness of our proposed method by the result of the evaluation experiment.